:root {
    --primary: #2e8b57;
    --bg: #e8f5e9;
    --card-bg: #ffffff;
    --text: #333;
}
body {
    font-family: 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
}
.container {
    background: var(--card-bg);
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    text-align: center;
    max-width: 500px;
    width: 100%;
    position: relative;
}

/* --- NÚT NGÔN NGỮ --- */
#lang-btn {
    position: absolute;
    top: 20px;
    right: 20px;
    background: transparent;
    border: 1px solid var(--primary);
    border-radius: 20px;
    padding: 4px 10px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    font-weight: bold;
    color: var(--primary);
    transition: 0.2s;
}
#lang-btn:hover { background-color: #f1f8e9; }
.flag-icon { width: 20px; height: 14px; border-radius: 2px; object-fit: cover; box-shadow: 0 0 2px rgba(0,0,0,0.2); }

h1 {
    color: var(--primary);
    margin-bottom: 10px;
    font-size: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}
p { color: #666; line-height: 1.6; margin-bottom: 25px; }

/* --- CẢNH BÁO ERASE FLASH (MỚI) --- */
.warning-box {
    background-color: #fff3cd; /* Nền vàng nhạt */
    color: #856404; /* Chữ vàng đậm */
    border: 1px solid #ffeeba;
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 25px;
    text-align: left;
    font-size: 0.95em;
    line-height: 1.5;
}
.highlight-erase {
    display: inline-block;
    background: white;
    color: #dc3545; /* Chữ đỏ */
    font-weight: bold;
    padding: 2px 6px;
    border-radius: 4px;
    border: 1px dashed #dc3545;
    margin-top: 5px;
}

.steps {
    text-align: left;
    background: #f8f9fa;
    padding: 20px;
    border-radius: 12px;
    margin-bottom: 30px;
    border-left: 4px solid var(--primary);
}
.steps h3 { margin: 0 0 10px 0; font-size: 16px; color: #444; }
.steps ol { margin: 0; padding-left: 20px; color: #555; }
.steps li { margin-bottom: 8px; }

esp-web-install-button { display: inline-block; margin-top: 10px; }

.driver-note {
    margin-top: 30px;
    font-size: 13px;
    color: #999;
    border-top: 1px solid #eee;
    padding-top: 15px;
}
.driver-note a { color: var(--primary); text-decoration: none; font-weight: bold; }
.driver-note a:hover { text-decoration: underline; }

.browser-support {
    background: #f8d7da;
    color: #721c24;
    padding: 10px;
    border-radius: 8px;
    font-size: 14px;
    margin-bottom: 20px;
    border: 1px solid #f5c6cb;
    display: none;
}